89 



HOP ALKALOIDS. 



BY PHILIP SCHIDROWITZ, PH.D., F.C.S. 



'""PHE term " Alkaloid " is nowadays generally understood to 

 denote organic bases occurring in nature, and is sometimes 

 still further restricted to such organic bases as occur in plants. 

 They are mostly of a markedly toxic nature. In addition to the 

 resins, oil, wax, &c., contained in the hop, there undoubtedly exist 

 small quantities of bodies of a distinctly alkaloidal nature. These 

 substances have not been studied as closely as some of the other 

 hop constituents, but at least one of them has been fully identified. 

 This is the well-known alkaloid morphine, to which further reference 

 will be made below. 



Historically LERMER (Chemisches Central-Blatt, 1863, 781) is 

 apparently the first to have claimed the isolation of an alkaloid from 

 hops. He obtained this substance, which, he affirmed, sublimes 

 in fine needles, from an ethereal extract of hops, by a process which 

 might reasonably be assumed to isolate alkaloidal substances if they 

 were present. The substance had an alkaline reaction, and contained 

 nitrogen, but was not further identified. 'GRIESSMAYER (C. 1874, 

 328) distilled an aqueous hop extract in the presence of potash. The 

 distillate so obtained was saturated with hydrochloric acid, evaporated, 

 the residue extracted with alcohol, the alcohol removed, and the 

 remanent hydrochlorates decomposed by means of alkali in the 

 presence of ether. He thus obtained an oil of a markedly alkaline 

 nature, which gave a number of characteristic reactions, and had an 

 odour strongly reminiscent of coniine. GRIESSMAYER named this 

 body " lupulin," and this has given rise to some confusion, as the 

 term "lupulin" is usually employed to denote the hop " flour." The 



